Cannot activate AppleTV

I cannot activate Apple TV on Xfinity. I use the same email, my Gmail address, to log into both Xfinity and Apple. When I try to activate Apple it tells me I must renew my Apple TV subscription, but my Xfinity subscription page lists the Apple TV as active. 

When I do continue to renew, it asks for my account and password, and it will not accept my Xfinity password. I'm assuming that it only recognizes me as an Apple account holder not as coming through Xfinity. 

I have spent over 3 hours on the phone with Xfinity agents trying to resolve this. They only tell me I must use a different email address. I have only one email address. This cannot be the solution. There must be other people who have only one email address and use both apple and Xfinity.